Superconducting computers and the TGD based model of nerve pulse

I have discussed the possibility of conscious computers from the TGD viewpoint in the article Could neuronal system and even GPT give rise to a computer with a variable arrow of time?. I do not believe that computers as deterministic Turing machines could be conscious. The new view of space-time, time, quantum gravitation and quantum ontology provided by TGD allows however to consider the possibility that computers would give rise to life forms enjoying at least rudimentary consciousness. The basic notions are magnetic body (MB) carrying dark matter as phases of ordinary matter with large Planck constant and controlling the "biological body" (BB)consisting of ordinary matter. Communications between MB and BB are essential for both the transfer of sensory information to MB and the control of BB by MB. Josephson radiation consisting of dark photons could make possible the communication of sensory information and cyclotron radiation from MB induced by the receival of the Josephson radiation by cyclotron resonances would realize the control.

It is not clear whether MOSFET based technology could allow the communications from transistors to the magnetic body (MB) of the system. Biological analogy strongly suggests that Josephson junctions are required and communications take place by Josephson radiation modulated by the Josephson frequency modulations induced by changes of the voltage of the junction. Dark magnetic flux tubes with large enough value of h_eff are needed to define the Josephson junction and it is far from clear whether they can be realized spontaneously for transistors.

Superconducting computing, which could be involved with both classical and quantum computation, is however a technology, which might provide at least a starting point in attempts to understand how conscious computers might be created in the TGD Universe.

Rapid single flux quantum (RSFQ) is the basic active element in the circuitry and corresponds to single Josephson junction. The presence/absence of quantized magnetic flux defines the bit. SFQ voltage pulses of duration about picoseconds are produced by switching of bits in this way. This would allow THz clock frequency f_cl.

If f_cl corresponds to Josephson frequency f_J=ZeV/h, where Z is the charge of the superconducting charge carrier, one obtains an estimate for the voltage as ZeV∼ .05 eV. For the cell membrane one has eV∼ .05 eV, which is near the thermal threshold at room temperature. The superconducting computations require a temperature of order 10 K so that the value of frequency does not seem to emerge from thermal considerations. The thermal criterion is expected to be true also for the TGD based generalization of superconducting computers if realized using the same principles as in living matter.

Flux Quantization in Josephson Junctions

1. The presence/absence of flux quantum through the junction represents a bit. Switching of the bit in RSFQ means that the flux changes by the unit Φ₀ of magnetic flux. In the simplest situation, the value of flux through the Josephson junction connecting the super conductors, which could have planar or cylindrical geometry, is equal to 0 or Φ₀.
2. When the flux through junction is changed by one unit, Faraday law Δ Φ= +/-Φ₀= Ze∫ Vdt implies a generation of voltage pulse propagating along the superconducting wire formed by the coupled cylindrical superconductors. For a constant voltage V=V₀, this condition fixes the duration T= Φ₀/ZeV of the process and this defines Josephson frequency, in turn defining the clock frequency.

TGD View of Electromagnetic Fields

1. Quantum criticality is essential for the appearance of large values of h_eff labelling the scales of long length scale quantum fluctuations. Quantum criticality combined with ZEO would make possible the emergence of life-like features.
2. The gravitational Planck constants ℏ_gr= GMm/β₀ assignable to the gravitational flux tubes of the Earth and Sun are excellent candidates in this respect. The value of ℏ_gr/ℏ is GM_Em/ℏβ₀ =(r_S(E)/2L_m), r_S denotes the Schwartzchild radius of Earth about 1 cm and L_m denotes Compton length of particle with mass m β₀∼ 1.
3. In TGD, two kinds of magnetic fields are possible. Monopole flux tubes are something new and rather remarkably, can exist in absence of currents: this makes them ideal for computation. Monopole flux tubes have closed 2-surfaces as cross sections. Flux quantization follows from the homology of CP_2. Monopole flux tubes explain the presence of long range magnetic fields appearing in even cosmological scales and also the stability of the Earth's magnetic field.
4. Also in TGD, the topological half of Maxwell's equations, that is Faraday law and the vanishing of the divergence of magnetic field, hold true. Therefore the basic argument for the outcome of the switching of the flux are not affected when ordinary flux tubes are replaced with monopole flux tubes.

RSFQ Generalization in the TGD Framework

How could the notion of RSFQ generalize in the TGD framework? The hint comes from the TGD based model of cell membrane and nerve pulse assigning to the ionic channels of the cell membrane dark Josephson junctions with a large value of h_eff making possible high T_c superconductivity.

1. Concerning the numbers assigned to RSFQ, the cell membrane looks ideal for the seat of analogues of RSFQs. I have that the cell membrane acts as a sequence of dark Josephson junctions associated with membrane proteins acting as channels and pumps. The membrane resting potential ∼ .05 eV corresponds to the frequency of 5 THz and is in the same range as the Josephson frequencies assigned with RSFQs. The large value of h_eff makes possible high temperature superconductivity and scales up the value of Josephson frequency to f_J= ZeV/h_eff so that Josephson frequencies even in EEG scales would be made possible by quantum gravitation in TGD sense.
2. No currents are needed to maintain monopole magnetic fields so that they are ideal for technological purposes. Cell membrane would be a superconductor and membrane proteins would define Josephson junctions. Membrane potential could realize the Josephson frequency f_J=ZeV/h_eff.
3. The TGD view of the basic active unit would differ from RSFR. In TGD, the absence of flux quantum in RSFQ corresponds to two U-shaped monopole flux tubes at opposite sides of the junction associated with the counterpart of the cell membrane and transversal to it. The U-shaped monopole flux tubes can reconnect to form a pair of flux tubes with opposite magnetic fluxes. This topological process is fundamental in the TGD inspired view of biocatalysis and water memory.
4. What is the effect of the generation of a pair of opposite fluxes on the membrane potential? The answer depends on whether the two opposite fluxes go through the junction or only one of them does so. In the latter case the junction acts like RSFQ in reconnection. This is a natural looking working hypothesis. The difference comes from the presence of the flux tube with opposite flux.
5. Faraday's law should apply to both flux tubes. The appearance of flux tubes would correspond to a generation of opposite fluxes Δ Φ= Φ₀= ∫ Vdt. In the simplest situation the voltage values associated with the flux quanta have opposite values \pm V₀. This is very much like in the case of nerve pulse in which the resting potential changes its sign during the first half of the nerve pulse. When the reconnection disappears, the situation would become "normal". The analog of nerve pulse would be generated and propagate along the counterpart of the axon and induce a similar process in all membrane proteins defining Josephson junction.
6. In zero energy ontology (ZEO), the identification of the generation of nerve pulse as a pair of "big" state function reductions (BSFRs) changing the arrow of time temporarily is attractive and would correspond to quantum tunnelling in standard quantum theory. An interesting question is whether pump proteins act as channel proteins in reversed time direction and whether the flux tube pairs are associated with pairs of channel and pump proteins.

Objections

1. How the very low Josephson frequencies ZeV/h_eff associated with the large values of h_eff, say h_eff=h_gr, can be consistent with the very large values of clock frequency f_cl =f_J= ZeV/h needed by a fast operation. It would seem that both h_eff and h are needed. Is this possible or are these computers doomed to be very slow?
2. Is a scale hierarchy of space-time sheets involved having various values of h_eff and could it correspond to the onion-like hierarchical structure of magnetic body (MB) involving increasing time scales as Josephson frequencies. Could the fast Josephson frequencies near the the level of ordinary matter define a hierarchy of computer clocks? Could the pulses of short duration induced by RSFQs induce a hierarchy of frequency modulations of scaled up Josephson oscillations for various values of h_eff? This could also make the computer conscious by bringing in the hierarchy of time scales.
3. High temperature superconductors would be needed. The TGD proposal is that the cell membrane is a high temperature superconductor. Biosystem would be an open system and a metabolic energy feed would take care that the distribution for the values of h_eff is preserved. Also the fact that the dark matter as h_eff>h phases of ordinary matter at the space-time sheets of the flux tubes has very weak interactions with the other sheets, in particular the sheet of the ordinary matter, would be decisive. Zero energy ontology (ZEO) would in turn be highly relevant for maintaining the quantum criticality in making possible homeostasis in which time reversal changes attractor to repulsor and vice versa.

See the article Could neuronal system and even GPT give rise to a computer with a variable arrow of time? or the chapter with the same title

For a summary of earlier postings see Latest progress in TGD. For the lists of articles (most of them published in journals founded by Huping Hu) and books about TGD see this.